Articles - 10

One of the first problems a capacitive-sensor analog designer must face is the low-frequency cutoff. Theoretically, you must fulfill just one simple requirement: a sufficiently large input resistance of the preamplifier's first stage. In ...

Synchronous rectifiers are MOSFETs, driven in such a way as to perform a rectifying function. They often take the place of diodes in the output-rectification stage of switching power converters, because of their lower on-state power loss. In power ...

A Zobel network is useful in making a reactive load appear as a pure resistance to a driving source prone to stability problems ( Reference 1 ). A typical situation is an audio power amplifier driving a loudspeaker, modeled at first approximation ...

A solar-powered lead-acid battery charger can ensure that the battery remains fully charged over a wide temperature range. The ideal charging circuit compensates for temperature and sunlight variations, including recovery from shading. Solar or ...

A bi-directional current source for a grounded load will always have some complication in its construction. The improved Howland Current Pump as shown in Figure 1 is the most frequent choice for this function. The Howland requires carefully matched ...

The analog priority amplifier shown in Figure 1 was originally conceived as part of a multiple output power supply where the voltage regulation was based on the level of the highest channel. Another application was an engine control system with an ...

Many engineers and designers are unaware of the advantages of using brushed DC motors as generators. Design engineers know that both brush DC and brushless DC (BLDC) motors can operate as generators, but many tend to avoid running brushed DC motors ...

Several years ago I wrote an article in Design Ideas called “Double µC’s PWM frequency resolution” ( Reference 1 ) where I mentioned how one can decrease the output ripple of a PWM-based DAC using two PWM signals having ...

Despite the increasing availability and declining cost of on-chip analog peripherals, the humble PWM DAC retains its appeal as a “free” DAC [ 1 ] that can repurpose an uncommitted DIO pin and counter/timer module, add a simple low pass ...

Most designers consider slowness in diodes to be an imperfection or a limitation. Why not take a more positive view of the situation? After all, a zener or an avalanche diode is no more than a diode with a limited breakdown voltage, and you can ...